Tubular boiler



(No Model.)

E. F. EDGAR TUBULAR BOILER.

No. 505,036. Patented Sept. 12, 1893.

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UNITED STATES PATENT OFFICE.

ELLIS F. EDGAR, OF WOODBRIDGE, NEW JERSEY.

TUBULAR BOILER.

SPECIFICATION forming part of Letters Patent No. 505,036, dated September 12, 1893.

Application filed September 21. 1892. Serial No. 446,399. (No model.)

To all whom it may concern:

Be it known that I, ELLIS F. EDGAR,a citizen of the United States of America, and a resident of Woodbridge, in the county of Middlesex and State of New J ersey,have invented certain new and useful Improvements in Tubular Boilers, of which the following is a specification, reference being had to the accompanying drawing, forming part of the same, which is a central vertical cross-sectional view of a boiler embodying niy present invention.

The invention consists in the combinations of devices hereinafter claimed whereby as one result the upper ends of the tubes are protected from too fierce a heat and the durability of the boiler thereby increased, and, as another, its efficiency is increased and a greater proportion of the heat unitsin the fuel are utilized within the boiler.

My desire is to use whatI call a heat accumulator, that is, a plate which Ihave devised which will not be destroyed by fire, which will be in the direct(straight line) path of the heat currents though not injuring the draft, and which preferably is composed of fire clay thatit maybecome highly heated. It thereby causes what has been described as a molecular bombardment of the atoms of consuming fuel one upon another which greatly increases the heat within the boiler and furthermore results in the almost entire exhaustion from said atoms of their heat units within the space desired to be heated. So too it insures the impinging of the flame and heat upon the tube Walls and utilizes it most efficiently for heating the surrounding water. If such a plate alone were arranged over the farther ends of the tubes they would be so highly heated above the water line, that they would speedily burn out or at least begin to leak. Now great heat is not especially desired above the water line. The task is to heat the water and I have therefore arranged a series of plates, one within each tube, at or about the level of the water line of the boiler, in the form of incombustible walls preferably conforming in shape to that of the interior of the tubes but a little smaller than the tubes thus leaving space for draft all around their edges, between the wall and interior Surface of the tube,the aggregate of cross area of such draft spaces being somewhere near the area of the draft exit, to prevent chok ng. I usually also set a second plate of simllar material over the ends of all of the tubes, supported upon the tube sheet but w th ample draft space between it and said tube sheet. It acts especially to work sharply the outer tubes, which is of advantage.

In the drawing 13, is the boiler having an exterior shell S, interior shell S, ashp1t A, firebox F, doors D, D, grate G, crown sheet 0, tubes T, tube sheet 6, walls W, and w, the latter within the tubes, and supported by rods '2", extending down from cross bars I), which extend across the upper ends of the tubes, cover a, and draft exit E, the steam space being of course, that part of the boiler above the water line and below the tube sheet. The tubes are preferably of good size four inches or more in diameter and when four inches I find that walls to, about (3%) three and one half inches in diameter give good results.

What I claim, and desire to secure by Letters Patent, is-

1. In a tubular boiler, the combination of an outer shell, an inner shell, a firebox, a tube sheet atthe fire box, a tube sheet at the smoke box, a series of fire tubes extending from one to the other of said tube sheets and a series of incombustible walls located within and partially closing said tubes at or about the water line of the boiler, but leaving draft spaces substantially at the side edges of said Wall, substantially as and for the purpose set forth.

2. A tubular boiler provided with an incombustible wall located in the smoke box and extending over the ends of the tubes at a distance therefrom, in combination with other incombustible walls located within the tubes at or about the water line and partially closing the same and draft spaces substantially at the side edges of said walls, all substan tially as set forth.

E. F. EDGAR.

Witnesses:

HERBERT J. ALLISON, CHAS. A. ALLISON. 

